JPH04214713A - Thermoplastic elastomer - Google Patents

Abstract

PURPOSE: To provide a thermoplastic elastomer selected from a group consisting of thermoplastic polyurethane, polyether ester and polyether amide especially equipped with oil swelling resistance, tensile strength and optical characteristics (transparency).

CONSTITUTION: A thermoplastic elastomer is derived from polyether polycarbonate diol as a diol constituent and this used polyether plycarbonate diol is characterized by constitution consisting of phosgene, dialkylcarbonate having a 1-4C alkyl group, cyclic carbonate having a 2-4C alkylene bridge or a mixture of them and polyoxyalkylene diol, aliphatic alkanediol, alicyclic alkanediol or alkyleneoxide.

COPYRIGHT: (C)1992,JPO

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD This invention relates to new thermoplastic elastomers selected from the group consisting of thermoplastic polyurethanes, polyether esters and polyether amides, which are derived from polyether polycarbonate diols as the diol component. It is something. The present invention also relates to a molded article manufactured using a thermoplastic elastomer of this type as an essential constituent material.

Thermoplastic elastomers selected from the group consisting of thermoplastic polyurethanes, polyetheresters and polyetheramides are required in industrial fields for the production of molded bodies for various purposes, such as the automobile manufacturing industry and the shoemaking industry. It is said that

0003

BACKGROUND OF THE INVENTION Polyether polyols or polyester polyols have been commonly used as the soft phase in such thermoplastic elastomers. For example, US Pat. Nos. 4,423,205 and 4,456,745
No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, 2003, discloses a method for producing polyurethane by the RIM method using a polycarbonate diol obtained from a cyclic carbonate. Furthermore, polyurethane made from poly(tetramethylene ether) glycol having a narrow molecular weight distribution is disclosed in European Patent Application Publication No. 167299.
It is stated in the No. Polyurethanes having polyether polycarbonate diols as the diol component are described in US Pat. No. 4,463,141, where the number average molecular weight (Mn) of the polyoxytetramethylene diol used is greater than 500. Polyether polycarbonate diols having aromatic structural units are described in German Patent Application No. 2726416, and European Patent Application No. 335416 discloses carbonate-modified polyoxytetramethylene glycols and processes for their production. .

However, none of these elastomers is necessarily fully satisfactory in terms of hydrolytic stability, mechanical properties, oil absorption properties, and optical properties. It is therefore an object of the present invention to provide thermoplastic elastomers selected from the group consisting of thermoplastic polyurethanes, polyetheresters and polyetheramides, with an improved set of properties.

[0005]

SUMMARY OF THE INVENTION However, the object mentioned above is a thermoplastic elastomer selected from the group consisting of thermoplastic polyurethanes, polyether esters and polyether amides, which are derived from polyether polycarbonate diols as the diol component. , the polyether polycarbonate diol used is phosgene, a dialkyl carbonate having a C1-C4 alkyl group or a C2
-A cyclic carbonate having a C4 alkylene bridge or a mixture thereof and a mixture of (a
1) 10 to 100 mol% polyoxytetramethylene diol having a number average molecular weight (Mn) of 150 to 500, and (a2) the above (a1) having C2-C8 alkylene groups.
), aliphatic alkanediols having 2 to 14 carbon atoms, cycloaliphatic alkanediols having 3 to 14 carbon atoms or alkylene oxides having 2 or 3 carbon atoms, or mixtures thereof It has been found by the inventors that this can be achieved with an elastomer characterized in that it is a reaction product with 0 to 90 mol % of a mixture.

[0006]

SUMMARY OF THE INVENTION The diol component of this new thermoplastic elastomer is derived from a polyether polycarbonate diol, which is a polyoxytetramethylene diol (also called polytetrahydrofuran or polyoxytetramethylene ether glycol). phosgene as carbonate component, dialkyl carbonates having C1-C4 alkyl groups or C2
It can be obtained by reacting with a cyclic carbonate having a -C4 alkylene bridge or a mixture thereof.

Polyoxytetramethylene diol (a1
) has a number average molecular weight (Mn) of 150 to 500, preferably 150 to 400. This can be obtained by catalytic polymerization of tetrahydrofuran by a known method.

[0008] If necessary, a mixture of this polyoxytetramethylene diol (a1) and other diols (a2) may be used. Suitable polyoxyalkylene diols different from (a1) are those having C2-C8 alkylene groups, especially C2-C4 alkylene groups. Preference is given to those having a relatively high molecular weight, especially a number average molecular weight (Mn) of 650 to 2000. Particularly suitable diols (a2) are straight-chain or branched alkanediols having 2 to 14 carbon atoms, especially ethanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol. Preferred are the diols 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol and 1,8-octanediol. Also cycloaliphatic diols having 3 to 15 carbon atoms, especially 1
, 4-dihydroxycyclohexane and 1,4-dihydroxymethylcyclohexane as well as ethylene oxide and propylene oxide can also be used. It is also possible to use mixtures of the abovementioned diols (a2).

Polyoxytetramethylene diol (a1
) and the other diols (a2) mentioned above contain from 10 to 100 mol %, in particular from 50 to 100 mol %, of polyoxytetramethylene diol (a1).

Preferred carbonate components are C1-C4
Dialkyl carbonates containing alkyl groups, especially dimethyl carbonate, diethyl carbonate and dipropyl carbonate. Examples of the cyclic carbonate having a C2-C4 alkylene bridge include ethylene carbonate, 1,2-propylene carbonate, 1,3-
Propylene carbonate is preferred. It is also possible to use mixtures of phosgene and the carbonates mentioned above as carbonate component.

Polyoxytetramethylene diol (a1
) and optionally further diols (a2) to the carbonate component varies depending on the desired molecular weight of the polyether polycarbonate diol and the carbonate used.

In some cases, a large amount of carbonate must be used, since some of the carbonate used is lost in the course of the reaction. In the case of phosgene, the amount of excess depends on the amount of phosgene that is driven off with the hydrochloric acid formed, and in the case of particularly preferred dialkyl carbonates, the carbonate used is equal to the alcohol formed in the transesterification. Depending on whether an azeotrope is to be formed, an excess of 0.5 to 50 mol %, in particular 5 to 35 mol %, is generally used.

The reaction of (a1) with the carbonate component of the mixture optionally with (a2) is preferably carried out in the presence of a catalyst.

The catalysts used are customary transesterification catalysts, such as tetraisopropyl orthotitanate, dibutyltin oxide, dibutyltin launate, zirconium (
IV) Acetylacetonates, alkali metal alcoholates such as sodium methylate, potassium methylate, sodium ethylate, potassium ethylate and the like are preferred. The amount of catalyst used is 0.00 based on the total amount of starting materials.
1 to 2%, especially 0.01 to 0.5%.

The reaction components are preferably boiled together with the catalyst and, if a dialkyl carbonate is used, the alcohol or azeotrope of carbonate and alcohol formed can be removed by distillation. Transesterification generally takes place at temperatures from 20 to 250°C, especially from 40 to 200°C. The temperature when using phosgene is between 0 and 100°C, preferably between 20 and 80°C. In this case, it is preferred to add a base, such as pyridine or triethylamine, to the reaction mass to neutralize the hydrochloric acid produced.

If an alkali metal alcoholate is used as catalyst, the reaction temperature is preferably from 20 to 150° C., in particular from 40 to 80° C., and the catalyst is neutralized with an acid, for example phosphoric acid, and then reacted with the corresponding acid. The alkali metal salt precipitate is removed by filtration.

When tetraisopropyl orthotitanate is used as a catalyst, the reaction temperature is between 40 and 25
A temperature of 0° C., especially 100 to 200° C. is preferred; excess catalyst can be deactivated after the reaction has ended, for example by adding phosphoric acid.

The reaction can be carried out under atmospheric pressure, reduced pressure or increased pressure. A vacuum of 0.1 to 5 mbar is applied at the end of the reaction to remove the relatively low-boiling final residue. The reaction is brought to an end when no more low-boiling constituents can be distilled off.

The resulting polyether polycarbonate diol has a molecular weight of 350 to 12,000, especially 500 to 6,000
It has a number average molecular weight (Mn) of

[0020] Thermoplastic polyurethanes, polyether esters and polyether amides can be produced by conventional methods known per se to those skilled in the art. That is, as mentioned above, a polyether polycarbonate diol obtained by reacting a carbonate component with compound (a1) and optionally further with compound (a2) is used as the diol component for the soft phase. . For further details of this method, which is known per se, reference may be made, if necessary, to the documents cited at the outset.

For thermoplastic polyurethanes, the polyether polycarbonate diols described above are reacted with organic isocyanates and chain extenders in a known manner. This can be done either by a one-shot method (ie, all three reacting components are reacted simultaneously) or by a prepolymer method (ie, a prepolymer of polyether polycarbonate diol and polyisocyanate is reacted with a chain extender).

Suitable polyisocyanates are all the polyisocyanates customary for the production of thermoplastic polyurethanes, such as diphenylmethane-4,4'-diisocyanate, toluylene-2,4-diisocyanate, toluylene-2,4-diisocyanate, and toluylene-2,4-diisocyanate. 2,6-diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2-(3-isocyanatopropyl)-cyclohexyl isocyanate and nuclear hydrogenated diphenylmethane-4,4'-diisocyanate. Isocyanates or mixtures thereof are used.

The chain extenders used are likewise compounds which are well known and customary for the production of thermoplastic polyurethanes, such as diols, diamines, dithiols, mercapto alcohols, amino alcohols, C2-
Thiols having a C9 alkyl group or mixtures thereof are used. Especially ethylene glycol, 1,3-
Propanediol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, 1,7
-heptanediol, 1,8-octanediol, 1,
9-nonanediol, neopentyl glycol, 2-butene-1,4-diol, 2-butene-1,4-diol, 2-butyl-2-ethyl-1,3-propanediol, 2-aminopropanol-1 Or 3-amino-
2,2'-dimethylpropanol is preferred. Further C
Diols, diamines and dithiols having 3-C14 cycloalkyl groups and optionally substituted with C1-C4 alkyl groups and mixtures thereof may also be used. Preferred is cyclohexanedimethanol. Also hydroquinone, resorcinol, p-cresol, p-aminophenol, 2,7-dihydroxynaphthalene, 4,4'
Aromatic and heterocyclic compounds such as -dihydroxybiphenol and 4,5-bis-(hydroxymethyl)-2-methylimidazole may also be used.

The reaction conditions for the polyisocyanate, polyether polycarbonate diol and chain extender are also known and are generally reacted at temperatures of 50 to 300°C.

The method for producing polyether ester and polyether amide is described, for example, in Chimica 28, 9 (
1974), p. 544 et seq. and J. Macromol
, Sci, A1(4) (1967), pages 617-625.

The new thermoplastic elastomers according to the invention are transparent, have good oil swelling resistance and excellent mechanical properties.

[0027]

EXAMPLES The OH number and number average molecular weight (Mn) shown in the following examples were measured as follows.

First, the number average molecular weight (Mn) is determined by the number of OH (M
n=112200/number of OH). The OH number was determined potentiometrically by the PSA method.

[0029]

[Example 1] Production of polyether polycarbonate diol (a) M
1,750 g (7.23 mol) of polyoxytetramethylene diol having n=242 and 743 g (6.3 mol) of diethyl carbonate are heated with 12.5 g (0.5%) of tetraisopropyl orthotitanate. , brought to a boil. Filling height of generated ethanol is 25cm and 5mm.
Unreacted diethyl carbonate was distilled off at a reflux rate of 4:1 under atmospheric pressure in a distillation column containing stainless steel net as packing. The reaction was carried out at 180°C and the relatively low boiling components were heated to 0.3 mbar (30 mbar).
It was removed under reduced pressure of Pa).

Yield = 1912 g Mn = 64 OH number = 64 (b) To produce polyether polycarbonate diol, 2000 g (8.3 mol) of polyoxytetramethylene diol with Mn = 242 was prepared in the same manner as in (a) above. )
, 743 g (6.3 mol) diethyl carbonate and 13.7 g (0.
5%) was used.

Yield = 2162 g Mn = 975 OH number = 115 (c) As a comparative experiment, 2925 g (4.5 mol) of polyoxytetramethylene diol with Mn = 649, 372 g (3.15 mol) of diethyl carbonate and tetraisopropyl Orthotitanate 16.5g (0.5%)
was reacted in the same manner as in section (a) above.

[0032] Yield = 3007g Mn=1968 Number of OH = 57

[0033]

Example 2 Production of thermoplastic polyurethane A special polyether polycarbonate diol (or polyoxytetramethylene diol in comparative experiment 2d in the table below) (the catalyst was deactivated by the addition of phosphoric acid) was heated at 110°C. After drying for 1 hour at 2 mbar, butanediol was added, the mixture was heated to 70 DEG C. and the diphenylmethane-4,4'-diisocyanate melt heated to 65 DEG C. was added with stirring.

Table 1 below summarizes the starting materials, their amounts used and the properties of the thermoplastic urethane obtained.

Oil swelling is determined by ASTM-3 oil absorption after 15 days storage at 100°C.

All types of resins are 59 to 60 (D
It has a Shore hardness D of IN53505).

The tensile strength is measured according to DIN 53455.

[0038]

[Table 1] According to the above, the novel thermoplastic elastomer according to the present invention has improved and good oil swelling resistance compared to polyether polycarbonate diol based on polyoxytetramethylene diol with Mn=649. , tensile strength, optical properties (transparency) and also exhibit significantly improved oil swelling resistance and transparency relative to the corresponding thermoplastic polyurethane based on polyoxytetramethylene diol with Mn=1979.

Claims (1)

[Claims] 1. A thermoplastic elastomer selected from the group consisting of thermoplastic polyurethanes, polyetheresters and polyetheramides, which is derived from and used as a diol component from a polyether polycarbonate diol. The ether polycarbonate diol is a mixture of phosgene, a dialkyl carbonate having a C1-C4 alkyl group or a cyclic carbonate having a C2-C4 alkylene bridge, or a mixture thereof, namely (a1) a number average molecular weight of from 150 to 500; 10 to 100 mol% polyoxytetramethylene diol having (Mn), and (a2) the above (a1) having a C2-C8 alkylene group.
), aliphatic alkanediols having 2 to 14 carbon atoms, cycloaliphatic alkanediols having 3 to 14 carbon atoms or alkylene oxides having 2 or 3 carbon atoms, or mixtures thereof An elastomer characterized in that it is a reaction product with a mixture of 0 to 90 mol %.